rfc9974.original   rfc9974.txt 
BIER Working Group G. Mirsky, Ed. Internet Engineering Task Force (IETF) G. Mirsky, Ed.
Internet-Draft Ericsson Request for Comments: 9974 Ericsson
Intended status: Informational N. Kumar Category: Informational N. Kumar
Expires: 27 May 2026 Oracle ISSN: 2070-1721 Oracle
M. Chen M. Chen
Huawei Technologies Huawei Technologies
S. Pallagatti, Ed. S. Pallagatti, Ed.
VMware VMware
23 November 2025 May 2026
Operations, Administration and Maintenance (OAM) Requirements for Bit Operations, Administration, and Maintenance (OAM) Requirements for the
Index Explicit Replication (BIER) Layer Bit Index Explicit Replication (BIER) Layer
draft-ietf-bier-oam-requirements-21
Abstract Abstract
This document specifies a list of functional requirements for This document specifies a list of functional requirements for
Operations, Administration, and Maintenance mechanisms, protocols, Operations, Administration, and Maintenance mechanisms, protocols,
and tools that support operations in the Bit Index Explicit and tools that support operations in the Bit Index Explicit
Replication layer of a network. Replication layer of a network.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This document is not an Internet Standards Track specification; it is
provisions of BCP 78 and BCP 79. published for informational purposes.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months This document is a product of the Internet Engineering Task Force
and may be updated, replaced, or obsoleted by other documents at any (IETF). It represents the consensus of the IETF community. It has
time. It is inappropriate to use Internet-Drafts as reference received public review and has been approved for publication by the
material or to cite them other than as "work in progress." Internet Engineering Steering Group (IESG). Not all documents
approved by the IESG are candidates for any level of Internet
Standard; see Section 2 of RFC 7841.
This Internet-Draft will expire on 27 May 2026. Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc9974.
Copyright Notice Copyright Notice
Copyright (c) 2025 IETF Trust and the persons identified as the Copyright (c) 2026 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction
1.1. Conventions used in this document . . . . . . . . . . . . 2 1.1. Conventions Used in This Document
1.1.1. Terminology . . . . . . . . . . . . . . . . . . . . . 2 1.1.1. Terminology
1.1.2. Requirements Language . . . . . . . . . . . . . . . . 3 1.1.2. Requirements Language
1.1.3. Acronyms . . . . . . . . . . . . . . . . . . . . . . 3 1.1.3. Acronyms
2. Requirements . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Requirements
3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 3. IANA Considerations
4. Security Considerations . . . . . . . . . . . . . . . . . . . 6 4. Security Considerations
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 7 5. References
6. Normative References . . . . . . . . . . . . . . . . . . . . 7 5.1. Normative References
7. Informative References . . . . . . . . . . . . . . . . . . . 7 5.2. Informative References
Contributors' Addresses . . . . . . . . . . . . . . . . . . . . . 9 Acknowledgements
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9 Contributors
Authors' Addresses
1. Introduction 1. Introduction
[RFC8279] specifies a Bit Index Explicit Replication (BIER) [RFC8279] specifies a Bit Index Explicit Replication (BIER)
architecture and how it supports forwarding of multicast data architecture and how it supports forwarding of multicast data
packets. packets.
This document lists the Operations, Administration, and Maintenance This document lists the Operations, Administration, and Maintenance
(OAM) requirements for the BIER layer (Section 4.2 of [RFC8279]) of (OAM) requirements for the BIER layer (see Section 4.2 of [RFC8279])
the multicast domain. The list can further be used for gap analysis of the multicast domain. The list can further be used for gap
of available OAM tools to identify possible enhancements of existing analysis of available OAM tools to identify whether possible
or whether new OAM tools are required to support proactive and on- enhancements of existing or new OAM tools are required to support
demand path monitoring and service validation. proactive and on-demand path monitoring and service validation.
1.1. Conventions used in this document 1.1. Conventions Used in This Document
1.1.1. Terminology 1.1.1. Terminology
The reader is expected to be familiar with: The reader is expected to be familiar with:
* [RFC7799], particularly definitions of Active, Passive, and Hybrid * [RFC7799], particularly definitions of Active, Passive, and Hybrid
measurement methods and metrics. measurement methods and metrics.
* The definitions and calculation of performance metrics, e.g., * The definitions and calculation of performance metrics, e.g.,
throughput, loss, delay, and delay variation metrics, are defined throughput, loss, delay, and delay variation metrics, are defined
in [RFC6374]. in [RFC6374].
* The definitions, applicability, and examples of the Continuity * The definitions, applicability, and examples of the Continuity
Check and Connectivity Verification mechanisms, components of the Check and Connectivity Verification mechanisms, components of the
Fault Management OAM, can be found in [RFC5860],[RFC6371], and Fault Management OAM, can be found in [RFC5860], [RFC6371], and
[RFC7276]. [RFC7276].
* A multicast domain is a network segment that defines the scope for * A multicast domain is a network segment that defines the scope for
the multicast traffic, allowing it to be exchanged only among multicast traffic, allowing it to be exchanged only among systems
systems within the domain [RFC8279]. within the domain [RFC8279].
* The term "BIER OAM" is used in this document interchangeably with * The term "BIER OAM" is used in this document interchangeably with
"a set of OAM protocols, methods, and tools for the BIER layer". "a set of OAM protocols, methods, and tools for the BIER layer".
* Downstream - is the direction from the ingress toward the egress * Downstream is the direction from the ingress toward the egress
endpoints of a multicast distribution tree. endpoints of a multicast distribution tree.
* Egress endpoint is a router to which the packet needs to be sent * Egress endpoint is a router to which the packet needs to be sent
[RFC8279]. [RFC8279].
* Ingress endpoint is a router that encapsulates a packet in a BIER * Ingress endpoint is a router that encapsulates a packet in a BIER
header [RFC8279]. header [RFC8279].
* A BIER OAM session is a communication established between Bit- * A BIER OAM session is a communication established between Bit-
Forwarding Routers (BFR) to perform OAM functions like fault Forwarding Routers (BFR) to perform OAM functions like fault
detection, performance monitoring, and localization [RFC7276]. detection, performance monitoring, and localization [RFC7276].
These sessions can be proactive (continuous, persistent These sessions can be proactive (continuous, persistent
configuration) or on-demand (manual, temporary diagnostics). configuration) or on-demand (manual, temporary diagnostics).
1.1.2. Requirements Language 1.1.2. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP "OPTIONAL" in this document are to be interpreted as described in
14 [RFC2119] [RFC8174] when, and only when, they appear in all BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here. capitals, as shown here.
The requirements language is used in Section 2 and applies to The requirements language is used in Section 2 and applies to
implementations of BIER OAM conformant to the listed requirements. implementations of BIER OAM conformant to the listed requirements.
1.1.3. Acronyms 1.1.3. Acronyms
BFD: Bidirectional Forwarding Detection [RFC8562] BFD: Bidirectional Forwarding Detection [RFC8562]
BFR: Bit-Forwarding Router [RFC8279] BFR: Bit-Forwarding Router [RFC8279]
BFER: Bit-Forwarding Egress Router [RFC8279] BFER: Bit-Forwarding Egress Router [RFC8279]
BIER: Bit Index Explicit Replication [RFC8279] BIER: Bit Index Explicit Replication [RFC8279]
OAM: Operations, Administration, and Maintenance [RFC6291]
PMTUD: Path Maximum Transmission Unit Discovery [RFC1191] OAM: Operations, Administration, and Maintenance [RFC6291]
p2mp: Point-to-Multipoint [RFC8562] PMTUD: Path Maximum Transmission Unit Discovery [RFC1191]
RDI: Remote Defect Indication [RFC6428] P2MP: Point-to-Multipoint [RFC8562]
STAMP: Simple Two-way Active Measurement Protocol [RFC8762] RDI: Remote Defect Indication [RFC6428]
STAMP: Simple Two-way Active Measurement Protocol [RFC8762]
2. Requirements 2. Requirements
This section lists the requirements for OAM of the BIER layer: This section lists the requirements for OAM of the BIER layer:
1. The listed requirements MUST be supported with any routing 1. The listed requirements MUST be supported with any routing
underlay [RFC8279] over which the BIER layer can be realized. underlay [RFC8279] over which the BIER layer can be realized.
2. It MUST be possible to initialize a BIER OAM session from any BFR 2. It MUST be possible to initialize a BIER OAM session from any
of the given BIER domain. BFR of the given BIER domain.
3. It MUST be possible to initialize a BIER OAM session from a 3. It MUST be possible to initialize a BIER OAM session from a
controller. controller.
4. BIER OAM MUST support proactive OAM monitoring and measurement 4. BIER OAM MUST support proactive OAM monitoring and measurement
methods. methods.
5. BIER OAM MUST support on-demand OAM monitoring and measurement 5. BIER OAM MUST support on-demand OAM monitoring and measurement
methods. methods.
6. BIER OAM MUST support active performance measurement methods 6. BIER OAM MUST support active performance measurement methods
[RFC7799]. [RFC7799].
7. BIER OAM MUST support passive performance measurement methods 7. BIER OAM MUST support passive performance measurement methods
[RFC7799]. [RFC7799].
8. BIER OAM MUST support the ability of any BFR in the given BIER 8. BIER OAM MUST support the ability of any BFR in the given BIER
domain to monitor Bit-Forwarding Egress Router (BFER) domain to proactively monitor Bit-Forwarding Egress Router
availability proactively. (BFER) availability.
This requirement provides helpful clarification to the combination of This requirement provides helpful clarification to the
Requirements 2 and 4. The p2mp BFD with active tail support combination of Requirements 2 and 4. The P2MP BFD with active
[RFC9780] is an example of a protocol that provides notifications tail support [RFC9780] is an example of a protocol that provides
about the loss of connectivity in a multicast distribution tree. notifications about the loss of connectivity in a multicast
distribution tree.
9. BIER OAM MUST support downstream path continuity check. 9. BIER OAM MUST support downstream path continuity checking.
Bidirectional Forwarding Detection (BFD) [RFC8562] is an example of a Bidirectional Forwarding Detection (BFD) [RFC8562] is an example
protocol that monitors the continuity of a multicast distribution of a protocol that monitors the continuity of a multicast
tree. distribution tree.
10. BIER OAM MUST support downstream performance measurement. 10. BIER OAM MUST support downstream performance measurement.
Simple Two-way Active Measurement Protocol (STAMP) [RFC8762] is an Simple Two-way Active Measurement Protocol (STAMP) [RFC8762] is
example of a protocol that supports measurement of performance an example of a protocol that supports measurement of
metrics, e.g., packet loss ratio, delay, and delay variation. performance metrics, e.g., packet loss ratio, delay, and delay
variation.
11. In the downstream direction, a BIER OAM solution MUST support 11. In the downstream direction, a BIER OAM solution MUST support
transmission of OAM packets to traverse the same set of nodes and transmission of OAM packets to traverse the same set of nodes
links and receive the same forwarding treatment (including QoS) and links and receive the same forwarding treatment (including
as the monitored BIER flow. QoS) as the monitored BIER flow.
In some cases, e.g., when monitoring a composite data flow that In some cases, e.g., when monitoring a composite data flow that
includes several sub-flows characterized by different CoS marking, an includes several sub-flows characterized by different Class-of-
operator may choose to monitor the continuity of the path at the Service (CoS) marking, an operator may choose to monitor the
highest CoS, not at every CoS value in the data flow. In that case, continuity of the path at the highest CoS, not at every CoS
BIER OAM packets traverse the same set of nodes and links as the value in the data flow. In that case, BIER OAM packets traverse
composite data flow while receiving the same forwarding treatment as the same set of nodes and links as the composite data flow while
the highest CoS sub-flow. In this scenario, the state of path receiving the same forwarding treatment as the highest CoS sub-
continuity for lower CoS sub-flows can be derived from the state of flow. In this scenario, the state of path continuity for lower
the highest CoS, as determined by the BIER OAM protocol performing CoS sub-flows can be derived from the state of the highest CoS,
continuity verification (e.g., BFD). as determined by the BIER OAM protocol performing continuity
verification (e.g., BFD).
12. BIER OAM MUST support bidirectional OAM methods. In the 12. BIER OAM MUST support bidirectional OAM methods. In the
downstream direction, these methods of monitoring or measurement downstream direction, these methods of monitoring or measurement
MUST conform to Requirement 11. In the reverse direction (i.e., MUST conform to Requirement 11. In the reverse direction (i.e.,
from the egress toward the ingress endpoint of the BIER OAM test from the egress toward the ingress endpoint of the BIER OAM test
session), BIER OAM packets MAY deviate from traversing the same session), BIER OAM packets MAY deviate from traversing the same
set of nodes and links, or receive a different forwarding set of nodes and links, or receive a different forwarding
treatment (including QoS) as the monitored BIER flow. treatment (including QoS) as the monitored BIER flow.
Point-to-Multipoint (p2mp) BFD with active tail [RFC9780]) is an Point-to-Multipoint (P2MP) BFD with active tail [RFC9780] is an
example of the bidirectional mechanism of continuity checking. example of the bidirectional mechanism of continuity checking.
13. BIER OAM MUST support Path Maximum Transmission Unit discovery 13. BIER OAM MUST support Path Maximum Transmission Unit Discovery
(PMTUD). (PMTUD).
The PMTUD using ICMP [RFC1191] is an example of the mechanism. The PMTUD using ICMP [RFC1191] is an example of the mechanism.
14. BIER OAM MUST support an RDI mechanism to notify the BFR, the 14. BIER OAM MUST support an RDI mechanism to notify the BFR, the
source of the continuity checking by BFERs. source of the continuity checking by BFERs.
The Diagnostic field in p2mp BFD with active tail support, as The Diagnostic field in P2MP BFD with active tail support, as
described in Section 5 of [RFC9780], is an example of the RDI described in Section 5 of [RFC9780], is an example of the RDI
mechanism. mechanism.
15. BIER OAM MUST support downstream performance measurement 15. BIER OAM MUST support downstream performance measurement
method(s) that (together) calculate performance metrics, e.g., method(s) that (together) calculate performance metrics, e.g.,
throughput, loss, delay, and delay variation metrics [RFC6374]. throughput, loss, delay, and delay variation metrics [RFC6374].
STAMP ([RFC8762] and [RFC8972]) is an example of an active STAMP ([RFC8762] and [RFC8972]) is an example of an active
performance measurement method of performance metrics that may be performance measurement method of performance metrics that may
applied in a BIER domain. The Alternate Marking Method, described in be applied in a BIER domain. The Alternate-Marking Method,
[RFC9341] and [RFC9342], is an example of a hybrid measurement method described in [RFC9341] and [RFC9342], is an example of a hybrid
([RFC7799]) that may be applied in a BIER domain. measurement method [RFC7799] that may be applied in a BIER
domain.
16. BIER OAM MUST support defect notification mechanism(s). 16. BIER OAM MUST support defect notification mechanism(s).
Alarm Indication Signal [RFC6427] is an example of the defect Alarm Indication Signal [RFC6427] is an example of the defect
notification mechanism. notification mechanism.
17. BIER OAM MUST support a way for any BFR in the given BIER domain 17. BIER OAM MUST support a way for any BFR in the given BIER domain
to originate a fault management message addressed to any subset to originate a fault management message addressed to any subset
of BFRs within the domain. of BFRs within the domain.
[RFC6427] provides an example of a Fault Management messaging [RFC6427] provides an example of a Fault Management messaging
mechanism. mechanism.
18. BIER OAM MUST support methods to enable the survivability of a 18. BIER OAM MUST support methods to enable the survivability of a
BIER layer. BIER layer.
Protection switching and restoration are examples of survivability Protection switching and restoration are examples of
methods. survivability methods.
3. IANA Considerations 3. IANA Considerations
This document does not propose any IANA consideration. This section This document has no IANA actions.
may be removed.
4. Security Considerations 4. Security Considerations
This document lists the OAM requirements for a BIER-enabled domain This document lists the OAM requirements for a BIER-enabled domain
and thus inherits the security considerations discussed in [RFC8279] and it thus inherits the security considerations discussed in
and [RFC8296]. Another general security aspect results from using [RFC8279] and [RFC8296]. Another general security aspect results
active OAM protocols ([RFC7799]) in a multicast network. from using active OAM protocols [RFC7799] in a multicast network.
Active OAM protocols inject specially constructed test packets. Some Active OAM protocols inject specially constructed test packets. Some
active OAM protocols are based on the echo request/reply principle of active OAM protocols are based on the echo request/reply principle of
using those test packets. In the multicast network, test packets are using those test packets. In the multicast network, test packets are
replicated as data packets, thus creating a possible amplification replicated as data packets, thus creating a possible amplification
effect of multiple echo replies being transmitted to the sender of effect of multiple echo replies being transmitted to the sender of
the echo request. Thus, following security-related requirements for the echo request. Therefore, the following security-related
BIER OAM: requirements are defined for BIER OAM:
* A BIER OAM solution MUST protect the control plane by controlling * A BIER OAM solution MUST protect the control plane by controlling
the rate of echo request transmission. the rate of echo request transmission.
* A BIER OAM solution MUST provide control of the number of BIER OAM * A BIER OAM solution MUST provide control of the number of BIER OAM
messages sent to the control plane. messages sent to the control plane.
5. Acknowledgements 5. References
The authors would like to thank the comments and suggestions from
Gunter van de Velde that helped improve this document.
6. Normative References 5.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC6374] Frost, D. and S. Bryant, "Packet Loss and Delay [RFC6374] Frost, D. and S. Bryant, "Packet Loss and Delay
Measurement for MPLS Networks", RFC 6374, Measurement for MPLS Networks", RFC 6374,
DOI 10.17487/RFC6374, September 2011, DOI 10.17487/RFC6374, September 2011,
<https://www.rfc-editor.org/info/rfc6374>. <https://www.rfc-editor.org/info/rfc6374>.
skipping to change at page 7, line 48 skipping to change at line 330
Explicit Replication (BIER)", RFC 8279, Explicit Replication (BIER)", RFC 8279,
DOI 10.17487/RFC8279, November 2017, DOI 10.17487/RFC8279, November 2017,
<https://www.rfc-editor.org/info/rfc8279>. <https://www.rfc-editor.org/info/rfc8279>.
[RFC8296] Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A., [RFC8296] Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A.,
Tantsura, J., Aldrin, S., and I. Meilik, "Encapsulation Tantsura, J., Aldrin, S., and I. Meilik, "Encapsulation
for Bit Index Explicit Replication (BIER) in MPLS and Non- for Bit Index Explicit Replication (BIER) in MPLS and Non-
MPLS Networks", RFC 8296, DOI 10.17487/RFC8296, January MPLS Networks", RFC 8296, DOI 10.17487/RFC8296, January
2018, <https://www.rfc-editor.org/info/rfc8296>. 2018, <https://www.rfc-editor.org/info/rfc8296>.
7. Informative References 5.2. Informative References
[RFC1191] Mogul, J. and S. Deering, "Path MTU discovery", RFC 1191, [RFC1191] Mogul, J. and S. Deering, "Path MTU discovery", RFC 1191,
DOI 10.17487/RFC1191, November 1990, DOI 10.17487/RFC1191, November 1990,
<https://www.rfc-editor.org/info/rfc1191>. <https://www.rfc-editor.org/info/rfc1191>.
[RFC5860] Vigoureux, M., Ed., Ward, D., Ed., and M. Betts, Ed., [RFC5860] Vigoureux, M., Ed., Ward, D., Ed., and M. Betts, Ed.,
"Requirements for Operations, Administration, and "Requirements for Operations, Administration, and
Maintenance (OAM) in MPLS Transport Networks", RFC 5860, Maintenance (OAM) in MPLS Transport Networks", RFC 5860,
DOI 10.17487/RFC5860, May 2010, DOI 10.17487/RFC5860, May 2010,
<https://www.rfc-editor.org/info/rfc5860>. <https://www.rfc-editor.org/info/rfc5860>.
skipping to change at page 9, line 27 skipping to change at line 403
T. Zhou, "Clustered Alternate-Marking Method", RFC 9342, T. Zhou, "Clustered Alternate-Marking Method", RFC 9342,
DOI 10.17487/RFC9342, December 2022, DOI 10.17487/RFC9342, December 2022,
<https://www.rfc-editor.org/info/rfc9342>. <https://www.rfc-editor.org/info/rfc9342>.
[RFC9780] Mirsky, G., Mishra, G., and D. Eastlake 3rd, [RFC9780] Mirsky, G., Mishra, G., and D. Eastlake 3rd,
"Bidirectional Forwarding Detection (BFD) for Multipoint "Bidirectional Forwarding Detection (BFD) for Multipoint
Networks over Point-to-Multipoint MPLS Label Switched Networks over Point-to-Multipoint MPLS Label Switched
Paths (LSPs)", RFC 9780, DOI 10.17487/RFC9780, May 2025, Paths (LSPs)", RFC 9780, DOI 10.17487/RFC9780, May 2025,
<https://www.rfc-editor.org/info/rfc9780>. <https://www.rfc-editor.org/info/rfc9780>.
Contributors' Addresses Acknowledgements
The authors would like to thank Gunter van de Velde for the comments
and suggestions that helped improve this document.
Contributors
Erik Nordmark Erik Nordmark
Email: nordmark@acm.org Email: nordmark@acm.org
Sam Aldrin Sam Aldrin
Google Google
Email: aldrin.ietf@gmail.com Email: aldrin.ietf@gmail.com
Lianshu Zheng Lianshu Zheng
Email: veronique_cheng@hotmail.com Email: veronique_cheng@hotmail.com
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